Door closer



March 20, 1962 S. R. GERTH ETAL DOOR CLOSER 2 Sheets-Sheet 2 Filed May 28, 1959 FIG.

FIG. 4

FIG. 6

FIG. 5

FIG. 8

INVENTORS SOL R. AVRUM s. KATZ,

GERTH 8 g g! VQZERGEL CARL ADLER BY ROBERT ATTORNEYS United States Patent Ofifice 3,026,104 Patented Mar. 20, 1962 3,026,104 DOOR CLOSER Sol R. Gerth, Avrum S. Katz, Carl Adler, and Robert J.

Spercel, Cleveland, Ohio, assignors to Sterling Industries, Inc, Cleveland, Ohio, a corporation of Ohio Filed May 28, 1959, Ser. No. 816,477 2 Claims. (Cl. 267-70) This invention relates to pneumatic door closers of the type intended for use with screen doors and storm doors and the like and particularly to pneumatic door closers which employ a compression spring which is loaded or compressed by opening of a door with which the device is associated and which also provides for metering of air from a chamber defined by a piston or plunger and associated housing to control return of the spring to its relatively uncompressed position.

A general object of the invention is to provide a door closer which is superior in operation and in trouble-free service to comparable door closers of the same general type and of comparable size and cost.

Another object of the invention is to provide a door closer having a sectional compression spring with guide members associated with the pairs of adjacent section ends, which guide means can be fabricated at low cost and lend themselves to easy assembly with the spring sections and which, most importantly, provide an effective overall spring length which is minimally increased from that of a unitary spring of the same length.

These and other objects and advantages of the invention will become more apparent from the following description of specific embodiments of the invention, which description is set forth merely by way of example and not by way of limitation.

In the drawings:

FIGURE 1 is a sectional view of a door closer body assembly contemplated by the invention.

FIGURE 2 is a cross-section taken from the plane of line 22 in FIGURE 1.

FIGURE 3 is a perspective view of one of the elements seen in FIGURES 1 and 2.

FIGURE 4 is a cross-section taken from the plane of line 44 in FIGURE 1.

FIGURE 5 is a fragmentary view similar to the left hand portion of FIGURE 1, certain of the elements having been altered.

FIGURE 6 is a cross-section taken from the plane of line 66 in FIGURE 5.

FIGURE 7 is a fragmentary magnified view of a portion of FIGURE 4.

FIGURE 8 is a fragmentary magnified View of a portion of FIGURE 6.

As shown in the drawings, there is provided a door closer having a rod or shaft 14 and a compression spring on the rod including the plurality of short spring sections 15. At the left end of the rod, as seen in FIGURE 1, is provided a plunger head to be described in greater detail below and which serves as an air plunger and also connects the left end of the spring consisting of the three spring sections 15 to the rod 14 for movement together during compression of the spring 15 against an abutment which comprises an end of the spring housing.

In use, the right end of the rod or shaft 14 is intended to be pivotally attached to a fixed bracket on a door jamb or lintel, as at a pivot pin hole 18. The left end of the housing of the door closer body is intended to be pivotally attached to a portion of the door, for example the top thereof, as at a pivot pin hole 19.

The above-mentioned housing comprises a shell 20 which is formed as an impact extrusion from an aluminum slug and which therefore extends integrally from a remaining unextruded portion of the slug indicated by the reference numeral 21. Accordingly, it will be understood that the shell 20 and the end block 21 together with the end wall portion of the housing 22 are all integrally formed from the same piece of metal.

The end wall of the housing opposite to the end Wall 22 is formed by an end disc 25 around which is rolled a lip 26 of the shell 20. An additional depression 27 may be formed in order to hold the disc 25 firmly in place. The disc 25 is annularly offset as illustrated in order to form a centering guide for the right hand end of the spring 15 as seen in FIGURE 1.

The plunger assembly comprises in the illustrated embodiment a rubber sealing cup 30 adapted, when properly supported, to sealingly engage the side Walls of the shell 20 when the head moves to the left, as seen in FIGURE 1, and adapted to readily pass air when the head moves to the right, as seen in FIGURE 1, all as is conventional. The sealing cup 30 is backed by a supporting washer 31 which has a central sleeve or hollow boss 32 extending I within the center of the sealing cup 30. Held against the opposite side of the supporting washer 31 from the cup 30 is a fibrous lubricant carrier in the form of a washer of felt or the like indicated by the reference numeral 35. An adapter Washer or cup 37 is positioned between the wiper member 35 and the left end (as seen in FIGURE 1) of the spring comprising the three spring sections 15, and acts as a centering support for such spring in a manner which will be apparent from the drawings.

Extending in the axial direction through the center of the plunger head subassembly is a small groove 45. This groove 45 is shown as having been formed in the inner surface of the sleeve or boss 32, as by scoring. The

groove communicates through the space 47 with the space within the housing on the left side of the plunger head. The groove 45 communicates at its other end with the space Within the housing on the right hand side of the plunger through the center of the wiper member 35 which may be radially spaced from the shaft 14 or which in any event is only loosely received thereon in' a relationship other than that which would require air from the groove 45 to pass through the wiper member. The wiper member 35 is Wetted with a liquid lubricant or oil and serves to apply such lubricant on the interior side of the shell 20 and at the same time functions as a Wiper to continuously clean such inside surface of the shell 20 and sweep any minute particles that may be deposited thereon toward one end or the other of the closer assembly, and predominantly toward the right end thereof, as seen in FIGURE 1.

The plunger head is held in assembled relation by a nut 55 which is tightened down against it to clamp the several elements of the plunger head between itself and the retaining ears 56 formed in the shaft 14. The portion between the nut 55 and the rubber cup 30 in the particular embodiment illustrated includes a pair of washers 60 and 61. The washer 61 functions to provide the rubber cup 30 with the pro-per support on its concave side. In the particular embodiment illustrated, the washer 61 is also dimpled as at 63 in order to hold the additional washer 60 in spaced relationship therefrom and define the space 47. The important point is that the groove extends in the axial direction at the central portion of the plunger head in the vicinity of the shaft 14 rather than at the periphery thereof or the radially intermediate portions thereon. The air metering passage thu communicates from one side of the plunger head to the other through its radially central portion. Such communication is also radially interior of the wiping member 35, air being exchanged passing under the inner edge of the wiping member 35, albeit around some portion of the annular extent of such inner edge. This important feature may be adapted to other techniques of fabricating the plunger assembly. For example, a shallow annular groove may be formed in the shaft 14 within the sleeve 32 allowing this sleeve to be crimped in retaining engagement in such a groove to dispose of the need for the elements such as the ears 56. The washer 61 may be similarly crimped onto the shaft 14. It would then be desirable to form the groove 45 in the shaft 14 rather than in the inside surface of the sleeve 32, and no element equivalent to the Washer 60 or to the nut 55 would be required.

An illustration of a structure in which the annular groove is formed in the shaft 14 is illustrated in FIGURES and 6. Here a shallow annular groove 65 is formed in the shaft 14 and within the sleeve 32 allowing the end of this sleeve to be crimped in retaining engagement in the groove thus restraining the washer 31 against movement in both axial directions and dispensing with the need for the retaining ears 56. The washer 61 is similarly crimped into an additional groove 66 formed on the shaft 14, The groove 45 on the inside surface of the sleeve 32 is replaced by a groove 67 in the shaft 14. No element such as the washer 60 or the nut 55 is required. The groove 67 is preferably deeper than it is wide to minimize the effects of possible slight variations in the amount of cross-sectional area in the crimping of a num-' ber of sleeves 32 over a number of shafts 14. Typical desirable dimensions would be a width of 0.12 inch and a depth of .025 inch for a door closer cylinder about 1 /2 inches in diameter and a shaft about .375 inch in diameter. Comparable dimensions are appropriate for the slot or groove 45 when that is used in the inside surface of the sleeve 32, although the width of such groove may be slightly increased if desired.

A drawback of the crimped-on plunger head shown in FIGURES 5 and 6 is that if the rubber sealing cup 30 requires replacement, the entire rod and plunger assembly must be replaced because the rubber cup cannot be independently removed. In many applications, however, the rubber cup is of a sufficiently self-supporting character that it becomes possible to greatly reduce the outside diameter of the washer 61 from that shown in FIGURE 5 so that the outside diameter of such washer only exceeds the outside diameter of the sleeve 32 by an amount sufficient to retain the rubber cup sealer 30 during operation but to allow the cup 30 to be removed by appropriate stretching and distortion and replaced when required.

Provided within each pair of adjacent ends of the short springs is a metal strap 70. The strap is bent into a box shape having two sidewalls 71 and 72 and two end walls 73 and 74. The end walls have openings 75 formed therein and receive the rod 14. The side edges of the sidewalls 71 and 72 have endwise portions of generally reduced width and also are formed with first portion 76, 77 and 78 which extend further from the axis of the rod 14 than does the inside diameter of the spring sections 15. Between the ends of such edges and such first portions' are other second portions 79 extending about the same distance from the axis of the rod 14 as does the inside diameter of the spring sections 15,

The ends of the spring sections 15 are squared or in other words are formed so that each end coil lies in a plane normal tothe axis of the spring when the spring is not deflected. Compression springs are commonly manufactured in this form. In the assembled condition, the end coils at adjacent ends of the short spring sections engage in the axial direction against each other and also against a plurality of the first portion 7 6-78 and the butt ends of such end coils each bottom against one of such first portions, namely the first portion 76. The springs may be assembled to each other by merely pressing the ends of two spring sections 15 over the opposite ends of one of the boxes shown in FIGURE 3. The abutting relationship against the projection 76 may be then estab-' lished or in any even-t will quickly establish itself as the spring is deflected a few times in use.

It will be understood that the strap box support for the spring sections provides a non-collapsing spring which will not buckle appreciably when the spring assembly is deflected (that is compressed) and which has a constant and reliable closing action. This specific means of supporting the pairs of adjacent ends of the spring sections is not critical to all aspects of the invention but it is highly advantageous. In any event it is important that a means of supporting the pairs of adjacent ends of the spring sections in centered relation be provided which will accomplish such support while minimizing the loss of effective overall spring length due to the support of the adjacent pairs of ends of the several spring sections. The end coils of the spring sections should be directly abutting.

The central support of the pairs of adjacent ends of the several spring sections is important in another aspect. When the spring structure as so far described is fully defiected in use as by the opening of a door, the spring comprising the three spring section 15 is almost fully compressed but any substantial coiling or curling thereof out of coaxial alignment with the central shaft 14 is prevented by the central support of such adjacent pairs of ends as above provided and by the division of the spring into the relatively short sections 15. Accordingly, if the associated door check is broken or if through some other accident the spring is deflected a slight distance further than normal so as to cause the coils thereof to come into contact with each other, the door closer will act as a strong positive draw bar or stop and both the door closer and the associated door will not as readily be destroyed as will conventional door closers of comparable size and cost.

It will be understood that as expanding movement of the spring 15 is completed, it is desirable to free the operation of the door closer from the restraining effect of the metering grooves 45 or 67 to allow the spring 15 to act effectively to fully close and latch the door. To this end, there is struck in the side of the housing tube 20 a notch or bypass groove 69 (FIGURE 1) which is operative in only the last half inch or so of the leftward travel of the plunger head, as seen in FIGURE 1.

In some cases, it may be desirable to include a small bumper spring 59 to reduce shock on the end wall 25 incident to full withdrawal of the rod 14.

Provided on the shaft 14 on the exterior side of the end wall 25 is a lock washer 57 having a sidewise pro jection 58 adapted to engage the end wall 25 to tilt the main body of the washer 57 and releasably lock the shaft 14 against leftward movement as seen in FIGURE 1. This lock washer may be employed only occasionally as during installation of the unit in order to temporarily hold the shaft 14 at a desired setting.

The invention is not restricted to the slavish imitation of each and every one of the details described above which have been set forth merely by way of example with the intent of most clearly setting forth the teaching of the invention. Obviously, devices may be provided which change, eliminate or add certain specific structural details without departing from the invention.

What is claimed is:

l. A spring rod assembly for door closers and the like comprising a rod, a compression spring on the rod, means connecting one end of the spring to the rod for movement together during compression of the spring against an abutment at the end of the spring opposite to said one end, said spring being divided along its length to provide a plurality of short springs, a support within each pair of adjacent ends of said short springs, each support being slidably mounted on said rod, said each support being formed to have central opening means slidably receiving said rod, radial outer extremities of said support comprising first portions extending further from the rod axis than does the inside diameter of the spring and other second portions extending the same distance from the rod axis as does the inside diameter of the spring, said first portions being engaged by the end coils of said short spring said Second portions engaging at said end coils with the inside diameter of said spring.

2. A spring rod assembly for door closers and the like comprising a rod, a compression spring on the rod, means connecting one end of the spring to the rod for movement together during compression of the spring against an abutment at the end of the spring opposite to said one end, said spring being divided along its length to provide a plurality of short springs, a metal strap within each pair of adjacent ends of said short springs, each strap being slidably mounted on said rod, said strap being bent into a box having two sidewalls and two end walls, said end walls having openings receiving said rod, side edges of said sidewalls being formed with first portions extending further from the rod axis than does the inside diameter of the spring and other second portions extending the same distance from the rod axis as does the inside diameter of the spring, the end coils at adjacent ends of said short springs engaging in the axial direction each against the other and also against a plurality of said first portions, the butt ends of said end coils each bottoming against one of said first portions, said second portions engaging at said end coils with the inside diameter of the spring.

References Cited in the file of this patent UNITED STATES PATENTS 1,712,914 Burnham May 14, 1929 1,750,917 Baker Mar. 18, 1930 2,183,640 Cornwell Dec. 19, 1939 2,363,538 Loepsinger Nov. 28, 1944 2,607,581 Love et al Aug. 19, 1952 2,702,398 Marcus Feb. 22, 1955 FOREIGN PATENTS 172,973 Germany July 4, 1906 

